Prof. Salvatore Greco - University of Portsmouth

Laver LT6 14:30-15:30

Two basic hypotheses in the classic models of decision analysis and decision theory are transitivity and completeness of preferences of considered individuals. The two axioms of transitivity and completeness, possibly together with some technical conditions, permit to represent preferences of individuals by means of utility functions that assign a numerical value to each alternative such that the greater the utility value the more preferred the alternatives. Significant empirical evidence as well as conceptual arguments has questioned completeness and transitivity. Consequently, a growing number of successful methodologies in decision analysis as well as much basic research in decision theory have weakened and even abandoned transitivity and completeness of the preferences. The basic idea of most of models proposed in this perspective is the representation of preferences by means of a plurality of utility functions or a plurality of subjective probability that can be interpreted in terms of a plurality of selves of the individual. An overview of this research will be presented and discussed.